The thermal decomposition of hydrocarbon containing material (i.e., pyrolysis) has been widely discussed. Both continuous and batch processes have been proposed and most of the processes described in the literature require an oxygen-free environment due to the high temperatures at which the process is performed.
Prior art, such as U.S. Pat. No. 4,301,750 (Fio Rito; November, 1981), the entire content of which is incorporated herein by reference, discuss continuous processes performed under a substantially oxygen-free environment. The main problem with such processes and apparatus is that seals are never totally reliable. Indeed, since continuous process requires continuous feed of material from the outside into the reactor, specific dynamic seals must be provided. Considering the important consequences of outside air leakage into the reactor chamber, it is considered an unacceptable risk to undertake thermal decomposition operations by use of a continuous process. Batch processes and apparatus such as, for example, the one disclosed in U.S. Pat. No. 5,821,396 (Bouzianne, R.; October, 1998) and U.S. Pat. No. 5,820,736 (Bouzianne, R. and R., Michaud; October, 1998), the entire content of which are incorporated herein by reference, are preferably used.
Processes for the thermal decomposition of material performed at elevated temperature, either continuous or batch processes require a substantially oxygen-free (i.e., anoxic) environment inside the reactor chamber (i.e., drum). The anoxic environment is essential since an oxygen (O2) leakage inside the apparatus (e.g., drum, reactor chamber) is likely to result in a violent explosion. This risk can be especially appreciated when considering that the thermal decomposition and cracking reactions are usually occurring in the temperature range of, for example, between 225° C. and 510° C. Thus, air (containing oxygen), has to be removed from the inside of the reactor chamber. Many apparatus and process rely on the use of a vacuum pump(s) to remove air from inside the reactor chamber. However, even if a complete vacuum inside the apparatus (e.g., drum, reactor chamber) is usually not a prerequisite, a substantially oxygen-free environment is required.
As it is the case for many prior art apparatus, the sealed reactor chamber of the batch process disclosed in U.S. Pat. No. 5,820,736 (Bouzianne, R. and R., Michaud; October, 1998) requires an almost complete vacuum to be created inside the drum reactor chamber to remove oxygen from therein. For this purpose, expensive vacuum pumps and seals are needed. Thus, creating a vacuum inside a reactor chamber is an expensive step.
It would be advantageous to have an improved method of (for) removing oxygen from a sealed closed space. Such improved method may be performed by way of a substance purge using a purge substance and more particularly an oxyphilic solution as described herein. The batch process described herein would then be advantageously achieved without the use of expensive vacuum pump and seals. Instead, a purge substance such as, for example, an oxyphilic solution may be loaded into a reactor and following sealing and heating of the reactor's interior to a predetermined temperature, the purge substance may allow the oxygen to be driven out of the interior of the container through a gas evacuation component. Unless otherwise indicated, percentages (%) are expressed on a basis of volume/volume (v/v).